[FFmpeg-user] Vorbis/Ogg duration

[Austen McRae]

Hey all,

I'm attempting to figure out if there is a header component of Vorbis (or
its container Ogg) that specifies the the audio duration.  My current make
of ffmpeg doesn't seem to place any type of duration information; when I
play it back using VLC it plays but the duration is 00:00, but I've been
able to find additional ogg vorbis files that do have a duration component
in VLC (which was exported from Quicktime).

Looking at the Ogg source files shows that the OGGStreamContext doesn't
really have a duration option, but it looks like we could add it using an
OggComment?  I did attempt to add it using the -metadata tag, but VLC
didn't pick up "duration" or "length" produced unplayable files...

Any additional knowledge as to how the duration is encoded would be great!

Sincerely,

Austen